幫忙轉為英文句子

Simple English that OK !!

Halo, I am sorry to tell you that , the shirts not suits for me since I bought from your shop last week. So I wanna change a bigger size back to your shop tomorrow.

Thanks for your co-operation !

Hello! Last week I bought two shirts (or dresses etc), but find that I don’t fit (or my child doesn’t fit) into that size. Can the two shirts (or dresses) be returned and exchanged for the next size up?

Note:
轉換大一個尺碼 = exchanged for the next size up
衫 ? Be specific, 恤衫, T-shirt, or dress

Can this sentence into English? thanks~Hello, last week bought two shirts, but find that size doesn't fit, you can return the converted large size?

I have bought two T-shirts in the last week, however, the size is not suit me,could I returns and exchanges in other size?

2012-06-07 11:16:21 補充：
前面加句 Hello,

Hi. I've bought two clothes from this shop last week, but found them too small afterwards, can you change them to a bigger size, please?